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- Meng, Qijun, 1990-, et al.
(författare)
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Integrating Cobalt-sites-rich Aza-fused Conjugated Microporous Polymers on BiVO4 for Efficient Photoelectrochemical Water Splitting
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Advanced surface and interface engineering has been demonstrated to be of critical importance for the development of photoanodes for highly efficient photoelectrochemical (PEC) water oxidation. In this study, cobalt-sites-rich aza-fused conjugated microporous polymer was integrated on the nanoporous bismuth vanadate electrode. The hybrid BiVO4/eCMP-Co photoanode exhibited a high photocurrent density of 4.3 mA cm-2 at 1.23 VRHE and a very low onset potential of ~ 0.2 VRHE with an applied bias photon to current efficiency of 1.62% at around 0.6 VRHE. Moreover, studies on charge carrier kinetics showed that eCMP-Co can not only accelerate water oxidation kinetics but also significantly suppress surface recombination, thereby dramatically increasing charge transfer efficiency. These results demonstrate the great potential of conjugated polymers combined with metal coordination as heterogenous catalysts on photoelectrodes in PEC devices.
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| 2. |
- Meng, Qijun, 1990-, et al.
(författare)
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Ultra-thin Nanolayers of Photodeposited Cobalt Phytate on BiVO4 for Efficient Photoelectrochemical Water Oxidation
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Strategical engineering of semiconducting films by loading co-catalysts is pivotal for optimizing the properties of photoelectrodes used for solar fuel production. In this study, an ultrathin layer of cobalt phytate (CoPhy) was integrated onto the nanoporous bismuth vanadate (BiVO4) photoanode by a simple photo-assisted electrodeposition method. The introduction of CoPhy significantly improved the PEC performance of BiVO4 photoanode, displaying a photocurrent density up to 4.3 mA cm-2 at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5G) and an impressive early onset of potential of ~0.2 VRHE as well as superior stability. Moreover, charge kinetics studies showed that the enhancement in PEC performance by CoPhy is primarily due to the suppression of surface recombination and acceleration of interfacial charge transfer.
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| 5. |
- Yang, Yi, et al.
(författare)
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Tuning catalytic activity of Ni-Co nanoparticles synthesized by gamma-radiolytic reduction of acetate aqueous solutions
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Transition metal-based catalysts show great potential to replace Pt-based material in energy conversion devices thanks to their low cost, reasonable intrinsic activity, thermodynamic stability, and corrosion resistance. The electrochemical performance of such catalysts is sensitive to their composition and structure. Here we demonstrate that homogeneous alloy nanoparticles with a varying Ni-to-Co ratio and controlled structure can be synthesized from aqueous Ni (Co) acetate solutions using a facile γ-radiolytic reduction method. The obtained samples are found to possess stacking fault defects that are ordered to form polytype structures. The concentration of these defects depends on the Ni-to-Co ratio, as supported by the results of ab initio calculations. Structural defects may play a significant role in the enhanced activity of catalysts toward oxygen evolution and oxygen reduction reactions. At the same time, the activity of Ni-Co catalysts in the hydrogen evolution reaction is found to be affected by the formation of Ni-OH bonds on the surface rather than by the presence of structural defects. Our study demonstrates that the composition of Ni-Co nanoparticles is an essential factor having an impact on their structure and that both composition and structure can be tuned to optimize electrochemical performance with respect to various catalytic reactions.
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| 7. |
- Yi, Xinlei, et al.
(författare)
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Distributed Event-Triggered Control for Global Consensus of Multi-Agent Systems with Input Saturation
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We consider the global consensus problem for multi-agent systems with input saturation over digraphs. Under a mild connectivity condition that the underlying digraph has a directed spanning tree, we use Lyapunov methods to show that the widely used distributed consensus protocol, which solves the consensus problem for the case without input saturation constraints, also solves the global consensus problem for the case with input saturation constraints. In order to reduce the overall need of communication and system updates, we then propose a distributed event-triggered control law. Global consensus is still realized and Zeno behavior is excluded. Numerical simulations are provided to illustrate the effectiveness of the theoretical results.
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